我在 ListView 中有一个单元格，里面有一堆文本。我显示了前两行文本，如果超出了，则以“...”结尾。我希望用户能够触摸单元格并让它在 View 中动态扩展，显示所有数据。然后，当他们再次触摸细胞时，它会收缩回正常大小。

我见过一个 iOS 应用可以做到这一点，它非常酷。有什么办法可以用 Android 做到这一点吗？怎么办？

最佳答案

我已经实现了一个适用于所有 Android SDK 版本的简单代码。

请参阅下面的工作原理和代码。

Github 代码:https://github.com/LeonardoCardoso/Animated-Expanding-ListView

有关我网站上的信息:http://android.leocardz.com/animated-expanding-listview/

基本上，您必须创建一个自定义的 TranslateAnimation 和一个自定义的列表适配器，并且在它进行动画处理时，您必须更新 ListView 项目的当前高度并通知适配器有关此更改。

让我们转到代码。

1. 列表项布局

   <?xml version="1.0" encoding="utf-8"?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
          android:id="@+id/text_wrap"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:orientation="horizontal"
          android:paddingBottom="@dimen/activity_vertical_margin"
          android:paddingLeft="@dimen/activity_horizontal_margin"
          android:paddingRight="@dimen/activity_horizontal_margin"
          android:paddingTop="@dimen/activity_vertical_margin" >
   
          <TextView
              android:id="@+id/text"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:textSize="18sp" >
          </TextView>
   
   </LinearLayout>
   

2. Activity 布局

      <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
             xmlns:tools="http://schemas.android.com/tools"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             tools:context=".MainActivity" >
   
             <ListView
                 android:id="@+id/list"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:divider="@android:color/black"
                 android:dividerHeight="3dp" >
             </ListView>
   
         </RelativeLayout>
   

3. 列表项类

   public class ListItem {
   
   private String text;
   private int collapsedHeight, currentHeight, expandedHeight;
   private boolean isOpen;
   private ListViewHolder holder;
   private int drawable;
   
   public ListItem(String text, int collapsedHeight, int currentHeight,
           int expandedHeight) {
       super();
       this.text = text;
       this.collapsedHeight = collapsedHeight;
       this.currentHeight = currentHeight;
       this.expandedHeight = expandedHeight;
       this.isOpen = false;
       this.drawable = R.drawable.down;
   }
   
   public String getText() {
       return text;
   }
   
   public void setText(String text) {
       this.text = text;
   }
   
   public int getCollapsedHeight() {
       return collapsedHeight;
   }
   
   public void setCollapsedHeight(int collapsedHeight) {
       this.collapsedHeight = collapsedHeight;
   }
   
   public int getCurrentHeight() {
       return currentHeight;
   }
   
   public void setCurrentHeight(int currentHeight) {
       this.currentHeight = currentHeight;
   }
   
   public int getExpandedHeight() {
       return expandedHeight;
   }
   
   public void setExpandedHeight(int expandedHeight) {
       this.expandedHeight = expandedHeight;
   }
   
   public boolean isOpen() {
       return isOpen;
   }
   
   public void setOpen(boolean isOpen) {
       this.isOpen = isOpen;
   }
   
   public ListViewHolder getHolder() {
       return holder;
   }
   
   public void setHolder(ListViewHolder holder) {
       this.holder = holder;
   }
   
   public int getDrawable() {
       return drawable;
   }
   
   public void setDrawable(int drawable) {
       this.drawable = drawable;
   }
   }
   

4. 查看Holder类

   public class ListViewHolder {
    private LinearLayout textViewWrap;
    private TextView textView;
   
    public ListViewHolder(LinearLayout textViewWrap, TextView textView) {
       super();
       this.textViewWrap = textViewWrap;
       this.textView = textView;
    }
   
    public TextView getTextView() {
           return textView;
    }
   
    public void setTextView(TextView textView) {
       this.textView = textView;
    }
   
    public LinearLayout getTextViewWrap() {
       return textViewWrap;
    }
   
    public void setTextViewWrap(LinearLayout textViewWrap) {
       this.textViewWrap = textViewWrap;
    }
   }
   

5. 自定义动画类

       public class ResizeAnimation extends Animation {
       private View mView;
       private float mToHeight;
       private float mFromHeight;
   
       private float mToWidth;
       private float mFromWidth;
   
       private ListAdapter mListAdapter;
       private ListItem mListItem;
   
       public ResizeAnimation(ListAdapter listAdapter, ListItem listItem,
               float fromWidth, float fromHeight, float toWidth, float toHeight) {
           mToHeight = toHeight;
           mToWidth = toWidth;
           mFromHeight = fromHeight;
           mFromWidth = fromWidth;
           mView = listItem.getHolder().getTextViewWrap();
           mListAdapter = listAdapter;
           mListItem = listItem;
           setDuration(200);
       }
   
       @Override
       protected void applyTransformation(float interpolatedTime, Transformation t) {
           float height = (mToHeight - mFromHeight) * interpolatedTime
                   + mFromHeight;
           float width = (mToWidth - mFromWidth) * interpolatedTime + mFromWidth;
           LayoutParams p = (LayoutParams) mView.getLayoutParams();
           p.height = (int) height;
           p.width = (int) width;
           mListItem.setCurrentHeight(p.height);
           mListAdapter.notifyDataSetChanged();
       }
     }
   

6. 自定义列表适配器类

   public class ListAdapter extends ArrayAdapter<ListItem> {
   private ArrayList<ListItem> listItems;
   private Context context;
   
   public ListAdapter(Context context, int textViewResourceId,
       ArrayList<ListItem> listItems) {
   super(context, textViewResourceId, listItems);
   this.listItems = listItems;
   this.context = context;
   }
   
   @Override
   @SuppressWarnings("deprecation")
   public View getView(int position, View convertView, ViewGroup parent) {
   ListViewHolder holder = null;
   ListItem listItem = listItems.get(position);
   
   if (convertView == null) {
       LayoutInflater vi = (LayoutInflater) context
               .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
       convertView = vi.inflate(R.layout.list_item, null);
   
       LinearLayout textViewWrap = (LinearLayout) convertView
               .findViewById(R.id.text_wrap);
       TextView text = (TextView) convertView.findViewById(R.id.text);
   
       holder = new ListViewHolder(textViewWrap, text);
   } else
       holder = (ListViewHolder) convertView.getTag();
   
   holder.getTextView().setText(listItem.getText());
   
   LayoutParams layoutParams = new LayoutParams(LayoutParams.FILL_PARENT,
           listItem.getCurrentHeight());
   holder.getTextViewWrap().setLayoutParams(layoutParams);
   
   holder.getTextView().setCompoundDrawablesWithIntrinsicBounds(
           listItem.getDrawable(), 0, 0, 0);
   
   convertView.setTag(holder);
   
   listItem.setHolder(holder);
   
   return convertView;
   }
   
   }
   

7. 主要 Activity

   public class MainActivity extends Activity {
   
   private ListView listView;
   private ArrayList<ListItem> listItems;
   private ListAdapter adapter;
   
   private final int COLLAPSED_HEIGHT_1 = 150, COLLAPSED_HEIGHT_2 = 200,
       COLLAPSED_HEIGHT_3 = 250;
   
   private final int EXPANDED_HEIGHT_1 = 250, EXPANDED_HEIGHT_2 = 300,
       EXPANDED_HEIGHT_3 = 350, EXPANDED_HEIGHT_4 = 400;
   
   private boolean accordion = true;
   
   @Override
   protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_main);
   
   listView = (ListView) findViewById(R.id.list);
   
   listItems = new ArrayList<ListItem>();
   mockItems();
   
   adapter = new ListAdapter(this, R.layout.list_item, listItems);
   
   listView.setAdapter(adapter);
   
   listView.setOnItemClickListener(new OnItemClickListener() {
   
       @Override
       public void onItemClick(AdapterView<?> parent, View view,
               int position, long id) {
           toggle(view, position);
       }
   });
   }
   
   private void toggle(View view, final int position) {
   ListItem listItem = listItems.get(position);
   listItem.getHolder().setTextViewWrap((LinearLayout) view);
   
   int fromHeight = 0;
   int toHeight = 0;
   
   if (listItem.isOpen()) {
       fromHeight = listItem.getExpandedHeight();
       toHeight = listItem.getCollapsedHeight();
   } else {
       fromHeight = listItem.getCollapsedHeight();
       toHeight = listItem.getExpandedHeight();
   
       // This closes all item before the selected one opens
       if (accordion) {
           closeAll();
       }
   }
   
   toggleAnimation(listItem, position, fromHeight, toHeight, true);
   }
   
   private void closeAll() {
   int i = 0;
   for (ListItem listItem : listItems) {
       if (listItem.isOpen()) {
           toggleAnimation(listItem, i, listItem.getExpandedHeight(),
                   listItem.getCollapsedHeight(), false);
       }
       i++;
   }
   }
   
   private void toggleAnimation(final ListItem listItem, final int position,
       final int fromHeight, final int toHeight, final boolean goToItem) {
   
   ResizeAnimation resizeAnimation = new ResizeAnimation(adapter,
           listItem, 0, fromHeight, 0, toHeight);
   resizeAnimation.setAnimationListener(new AnimationListener() {
   
       @Override
       public void onAnimationStart(Animation animation) {
       }
   
       @Override
       public void onAnimationRepeat(Animation animation) {
       }
   
       @Override
       public void onAnimationEnd(Animation animation) {
           listItem.setOpen(!listItem.isOpen());
           listItem.setDrawable(listItem.isOpen() ? R.drawable.up
                   : R.drawable.down);
           listItem.setCurrentHeight(toHeight);
           adapter.notifyDataSetChanged();
   
           if (goToItem)
               goToItem(position);
       }
   });
   
   listItem.getHolder().getTextViewWrap().startAnimation(resizeAnimation);
   }
   
   private void goToItem(final int position) {
   listView.post(new Runnable() {
       @Override
       public void run() {
           try {
               listView.smoothScrollToPosition(position);
           } catch (Exception e) {
               listView.setSelection(position);
           }
       }
   });
   }
   
   private void mockItems() {
   listItems
           .add(new ListItem(
                   "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
                   COLLAPSED_HEIGHT_1, COLLAPSED_HEIGHT_1,
                   EXPANDED_HEIGHT_1));
   
   listItems
           .add(new ListItem(
                   "Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.",
                   COLLAPSED_HEIGHT_2, COLLAPSED_HEIGHT_2,
                   EXPANDED_HEIGHT_2));
   
   listItems
           .add(new ListItem(
                   "Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.",
                   COLLAPSED_HEIGHT_3, COLLAPSED_HEIGHT_3,
                   EXPANDED_HEIGHT_3));
   
   listItems
           .add(new ListItem(
                   "Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo.",
                   COLLAPSED_HEIGHT_2, COLLAPSED_HEIGHT_2,
                   EXPANDED_HEIGHT_4));
   
   listItems
           .add(new ListItem(
                   "At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga.",
                   COLLAPSED_HEIGHT_1, COLLAPSED_HEIGHT_1,
                   EXPANDED_HEIGHT_4));
   
   listItems
           .add(new ListItem(
                   "Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus.",
                   COLLAPSED_HEIGHT_2, COLLAPSED_HEIGHT_2,
                   EXPANDED_HEIGHT_4));
   
   listItems
           .add(new ListItem(
                   "Temporibus autem quibusdam et aut officiis debitis aut rerum necessitatibus saepe eveniet ut et voluptates repudiandae sint et molestiae non recusandae.",
                   COLLAPSED_HEIGHT_3, COLLAPSED_HEIGHT_3,
                   EXPANDED_HEIGHT_3));
   
   listItems
           .add(new ListItem(
                   "Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.",
                   COLLAPSED_HEIGHT_1, COLLAPSED_HEIGHT_1,
                   EXPANDED_HEIGHT_4));
   
       }
   
   }
   

关于java - 如何使 Android 中的 ListView 中的单元格在被触​​摸时垂直扩展和收缩？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12522348/